This is an investigator-intiated, double-blind, randomized, placebo-controlled study to determine if troglitazone improves insulin resistance and metabolic control in adolescents with Type I diabetes. Thirty (30) subjects will be randomized to receive troglitazone or placebo for 4 months. Metabolic control, insulin sensitivity will be determined at baseline and 4 months. Insulin sensitivity will be evaluated using the euglycemic hyperinsulinemic clamp technique.